1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) ST-Ericsson SA 2010
4  *
5  * Author: Naveen Kumar G <naveen.gaddipati@stericsson.com> for ST-Ericsson
6  * Author: Sundar Iyer <sundar.iyer@stericsson.com> for ST-Ericsson
7  *
8  * Keypad controller driver for the SKE (Scroll Key Encoder) module used in
9  * the Nomadik 8815 and Ux500 platforms.
10  */
11 
12 #include <linux/platform_device.h>
13 #include <linux/interrupt.h>
14 #include <linux/spinlock.h>
15 #include <linux/io.h>
16 #include <linux/delay.h>
17 #include <linux/input.h>
18 #include <linux/slab.h>
19 #include <linux/clk.h>
20 #include <linux/module.h>
21 
22 #include <linux/platform_data/keypad-nomadik-ske.h>
23 
24 /* SKE_CR bits */
25 #define SKE_KPMLT	(0x1 << 6)
26 #define SKE_KPCN	(0x7 << 3)
27 #define SKE_KPASEN	(0x1 << 2)
28 #define SKE_KPASON	(0x1 << 7)
29 
30 /* SKE_IMSC bits */
31 #define SKE_KPIMA	(0x1 << 2)
32 
33 /* SKE_ICR bits */
34 #define SKE_KPICS	(0x1 << 3)
35 #define SKE_KPICA	(0x1 << 2)
36 
37 /* SKE_RIS bits */
38 #define SKE_KPRISA	(0x1 << 2)
39 
40 #define SKE_KEYPAD_ROW_SHIFT	3
41 #define SKE_KPD_NUM_ROWS	8
42 #define SKE_KPD_NUM_COLS	8
43 
44 /* keypad auto scan registers */
45 #define SKE_ASR0	0x20
46 #define SKE_ASR1	0x24
47 #define SKE_ASR2	0x28
48 #define SKE_ASR3	0x2C
49 
50 #define SKE_NUM_ASRX_REGISTERS	(4)
51 #define	KEY_PRESSED_DELAY	10
52 
53 /**
54  * struct ske_keypad  - data structure used by keypad driver
55  * @irq:	irq no
56  * @reg_base:	ske registers base address
57  * @input:	pointer to input device object
58  * @board:	keypad platform device
59  * @keymap:	matrix scan code table for keycodes
60  * @clk:	clock structure pointer
61  */
62 struct ske_keypad {
63 	int irq;
64 	void __iomem *reg_base;
65 	struct input_dev *input;
66 	const struct ske_keypad_platform_data *board;
67 	unsigned short keymap[SKE_KPD_NUM_ROWS * SKE_KPD_NUM_COLS];
68 	struct clk *clk;
69 	struct clk *pclk;
70 	spinlock_t ske_keypad_lock;
71 };
72 
73 static void ske_keypad_set_bits(struct ske_keypad *keypad, u16 addr,
74 		u8 mask, u8 data)
75 {
76 	u32 ret;
77 
78 	spin_lock(&keypad->ske_keypad_lock);
79 
80 	ret = readl(keypad->reg_base + addr);
81 	ret &= ~mask;
82 	ret |= data;
83 	writel(ret, keypad->reg_base + addr);
84 
85 	spin_unlock(&keypad->ske_keypad_lock);
86 }
87 
88 /*
89  * ske_keypad_chip_init: init keypad controller configuration
90  *
91  * Enable Multi key press detection, auto scan mode
92  */
93 static int __init ske_keypad_chip_init(struct ske_keypad *keypad)
94 {
95 	u32 value;
96 	int timeout = keypad->board->debounce_ms;
97 
98 	/* check SKE_RIS to be 0 */
99 	while ((readl(keypad->reg_base + SKE_RIS) != 0x00000000) && timeout--)
100 		cpu_relax();
101 
102 	if (timeout == -1)
103 		return -EINVAL;
104 
105 	/*
106 	 * set debounce value
107 	 * keypad dbounce is configured in DBCR[15:8]
108 	 * dbounce value in steps of 32/32.768 ms
109 	 */
110 	spin_lock(&keypad->ske_keypad_lock);
111 	value = readl(keypad->reg_base + SKE_DBCR);
112 	value = value & 0xff;
113 	value |= ((keypad->board->debounce_ms * 32000)/32768) << 8;
114 	writel(value, keypad->reg_base + SKE_DBCR);
115 	spin_unlock(&keypad->ske_keypad_lock);
116 
117 	/* enable multi key detection */
118 	ske_keypad_set_bits(keypad, SKE_CR, 0x0, SKE_KPMLT);
119 
120 	/*
121 	 * set up the number of columns
122 	 * KPCN[5:3] defines no. of keypad columns to be auto scanned
123 	 */
124 	value = (keypad->board->kcol - 1) << 3;
125 	ske_keypad_set_bits(keypad, SKE_CR, SKE_KPCN, value);
126 
127 	/* clear keypad interrupt for auto(and pending SW) scans */
128 	ske_keypad_set_bits(keypad, SKE_ICR, 0x0, SKE_KPICA | SKE_KPICS);
129 
130 	/* un-mask keypad interrupts */
131 	ske_keypad_set_bits(keypad, SKE_IMSC, 0x0, SKE_KPIMA);
132 
133 	/* enable automatic scan */
134 	ske_keypad_set_bits(keypad, SKE_CR, 0x0, SKE_KPASEN);
135 
136 	return 0;
137 }
138 
139 static void ske_keypad_report(struct ske_keypad *keypad, u8 status, int col)
140 {
141 	int row = 0, code, pos;
142 	struct input_dev *input = keypad->input;
143 	u32 ske_ris;
144 	int key_pressed;
145 	int num_of_rows;
146 
147 	/* find out the row */
148 	num_of_rows = hweight8(status);
149 	do {
150 		pos = __ffs(status);
151 		row = pos;
152 		status &= ~(1 << pos);
153 
154 		code = MATRIX_SCAN_CODE(row, col, SKE_KEYPAD_ROW_SHIFT);
155 		ske_ris = readl(keypad->reg_base + SKE_RIS);
156 		key_pressed = ske_ris & SKE_KPRISA;
157 
158 		input_event(input, EV_MSC, MSC_SCAN, code);
159 		input_report_key(input, keypad->keymap[code], key_pressed);
160 		input_sync(input);
161 		num_of_rows--;
162 	} while (num_of_rows);
163 }
164 
165 static void ske_keypad_read_data(struct ske_keypad *keypad)
166 {
167 	u8 status;
168 	int col = 0;
169 	int ske_asr, i;
170 
171 	/*
172 	 * Read the auto scan registers
173 	 *
174 	 * Each SKE_ASRx (x=0 to x=3) contains two row values.
175 	 * lower byte contains row value for column 2*x,
176 	 * upper byte contains row value for column 2*x + 1
177 	 */
178 	for (i = 0; i < SKE_NUM_ASRX_REGISTERS; i++) {
179 		ske_asr = readl(keypad->reg_base + SKE_ASR0 + (4 * i));
180 		if (!ske_asr)
181 			continue;
182 
183 		/* now that ASRx is zero, find out the coloumn x and row y */
184 		status = ske_asr & 0xff;
185 		if (status) {
186 			col = i * 2;
187 			ske_keypad_report(keypad, status, col);
188 		}
189 		status = (ske_asr & 0xff00) >> 8;
190 		if (status) {
191 			col = (i * 2) + 1;
192 			ske_keypad_report(keypad, status, col);
193 		}
194 	}
195 }
196 
197 static irqreturn_t ske_keypad_irq(int irq, void *dev_id)
198 {
199 	struct ske_keypad *keypad = dev_id;
200 	int timeout = keypad->board->debounce_ms;
201 
202 	/* disable auto scan interrupt; mask the interrupt generated */
203 	ske_keypad_set_bits(keypad, SKE_IMSC, ~SKE_KPIMA, 0x0);
204 	ske_keypad_set_bits(keypad, SKE_ICR, 0x0, SKE_KPICA);
205 
206 	while ((readl(keypad->reg_base + SKE_CR) & SKE_KPASON) && --timeout)
207 		cpu_relax();
208 
209 	/* SKEx registers are stable and can be read */
210 	ske_keypad_read_data(keypad);
211 
212 	/* wait until raw interrupt is clear */
213 	while ((readl(keypad->reg_base + SKE_RIS)) && --timeout)
214 		msleep(KEY_PRESSED_DELAY);
215 
216 	/* enable auto scan interrupts */
217 	ske_keypad_set_bits(keypad, SKE_IMSC, 0x0, SKE_KPIMA);
218 
219 	return IRQ_HANDLED;
220 }
221 
222 static int __init ske_keypad_probe(struct platform_device *pdev)
223 {
224 	const struct ske_keypad_platform_data *plat =
225 			dev_get_platdata(&pdev->dev);
226 	struct ske_keypad *keypad;
227 	struct input_dev *input;
228 	struct resource *res;
229 	int irq;
230 	int error;
231 
232 	if (!plat) {
233 		dev_err(&pdev->dev, "invalid keypad platform data\n");
234 		return -EINVAL;
235 	}
236 
237 	irq = platform_get_irq(pdev, 0);
238 	if (irq < 0) {
239 		dev_err(&pdev->dev, "failed to get keypad irq\n");
240 		return -EINVAL;
241 	}
242 
243 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
244 	if (!res) {
245 		dev_err(&pdev->dev, "missing platform resources\n");
246 		return -EINVAL;
247 	}
248 
249 	keypad = kzalloc(sizeof(struct ske_keypad), GFP_KERNEL);
250 	input = input_allocate_device();
251 	if (!keypad || !input) {
252 		dev_err(&pdev->dev, "failed to allocate keypad memory\n");
253 		error = -ENOMEM;
254 		goto err_free_mem;
255 	}
256 
257 	keypad->irq = irq;
258 	keypad->board = plat;
259 	keypad->input = input;
260 	spin_lock_init(&keypad->ske_keypad_lock);
261 
262 	if (!request_mem_region(res->start, resource_size(res), pdev->name)) {
263 		dev_err(&pdev->dev, "failed to request I/O memory\n");
264 		error = -EBUSY;
265 		goto err_free_mem;
266 	}
267 
268 	keypad->reg_base = ioremap(res->start, resource_size(res));
269 	if (!keypad->reg_base) {
270 		dev_err(&pdev->dev, "failed to remap I/O memory\n");
271 		error = -ENXIO;
272 		goto err_free_mem_region;
273 	}
274 
275 	keypad->pclk = clk_get(&pdev->dev, "apb_pclk");
276 	if (IS_ERR(keypad->pclk)) {
277 		dev_err(&pdev->dev, "failed to get pclk\n");
278 		error = PTR_ERR(keypad->pclk);
279 		goto err_iounmap;
280 	}
281 
282 	keypad->clk = clk_get(&pdev->dev, NULL);
283 	if (IS_ERR(keypad->clk)) {
284 		dev_err(&pdev->dev, "failed to get clk\n");
285 		error = PTR_ERR(keypad->clk);
286 		goto err_pclk;
287 	}
288 
289 	input->id.bustype = BUS_HOST;
290 	input->name = "ux500-ske-keypad";
291 	input->dev.parent = &pdev->dev;
292 
293 	error = matrix_keypad_build_keymap(plat->keymap_data, NULL,
294 					   SKE_KPD_NUM_ROWS, SKE_KPD_NUM_COLS,
295 					   keypad->keymap, input);
296 	if (error) {
297 		dev_err(&pdev->dev, "Failed to build keymap\n");
298 		goto err_clk;
299 	}
300 
301 	input_set_capability(input, EV_MSC, MSC_SCAN);
302 	if (!plat->no_autorepeat)
303 		__set_bit(EV_REP, input->evbit);
304 
305 	error = clk_prepare_enable(keypad->pclk);
306 	if (error) {
307 		dev_err(&pdev->dev, "Failed to prepare/enable pclk\n");
308 		goto err_clk;
309 	}
310 
311 	error = clk_prepare_enable(keypad->clk);
312 	if (error) {
313 		dev_err(&pdev->dev, "Failed to prepare/enable clk\n");
314 		goto err_pclk_disable;
315 	}
316 
317 
318 	/* go through board initialization helpers */
319 	if (keypad->board->init)
320 		keypad->board->init();
321 
322 	error = ske_keypad_chip_init(keypad);
323 	if (error) {
324 		dev_err(&pdev->dev, "unable to init keypad hardware\n");
325 		goto err_clk_disable;
326 	}
327 
328 	error = request_threaded_irq(keypad->irq, NULL, ske_keypad_irq,
329 				     IRQF_ONESHOT, "ske-keypad", keypad);
330 	if (error) {
331 		dev_err(&pdev->dev, "allocate irq %d failed\n", keypad->irq);
332 		goto err_clk_disable;
333 	}
334 
335 	error = input_register_device(input);
336 	if (error) {
337 		dev_err(&pdev->dev,
338 				"unable to register input device: %d\n", error);
339 		goto err_free_irq;
340 	}
341 
342 	if (plat->wakeup_enable)
343 		device_init_wakeup(&pdev->dev, true);
344 
345 	platform_set_drvdata(pdev, keypad);
346 
347 	return 0;
348 
349 err_free_irq:
350 	free_irq(keypad->irq, keypad);
351 err_clk_disable:
352 	clk_disable_unprepare(keypad->clk);
353 err_pclk_disable:
354 	clk_disable_unprepare(keypad->pclk);
355 err_clk:
356 	clk_put(keypad->clk);
357 err_pclk:
358 	clk_put(keypad->pclk);
359 err_iounmap:
360 	iounmap(keypad->reg_base);
361 err_free_mem_region:
362 	release_mem_region(res->start, resource_size(res));
363 err_free_mem:
364 	input_free_device(input);
365 	kfree(keypad);
366 	return error;
367 }
368 
369 static int ske_keypad_remove(struct platform_device *pdev)
370 {
371 	struct ske_keypad *keypad = platform_get_drvdata(pdev);
372 	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
373 
374 	free_irq(keypad->irq, keypad);
375 
376 	input_unregister_device(keypad->input);
377 
378 	clk_disable_unprepare(keypad->clk);
379 	clk_put(keypad->clk);
380 
381 	if (keypad->board->exit)
382 		keypad->board->exit();
383 
384 	iounmap(keypad->reg_base);
385 	release_mem_region(res->start, resource_size(res));
386 	kfree(keypad);
387 
388 	return 0;
389 }
390 
391 #ifdef CONFIG_PM_SLEEP
392 static int ske_keypad_suspend(struct device *dev)
393 {
394 	struct platform_device *pdev = to_platform_device(dev);
395 	struct ske_keypad *keypad = platform_get_drvdata(pdev);
396 	int irq = platform_get_irq(pdev, 0);
397 
398 	if (device_may_wakeup(dev))
399 		enable_irq_wake(irq);
400 	else
401 		ske_keypad_set_bits(keypad, SKE_IMSC, ~SKE_KPIMA, 0x0);
402 
403 	return 0;
404 }
405 
406 static int ske_keypad_resume(struct device *dev)
407 {
408 	struct platform_device *pdev = to_platform_device(dev);
409 	struct ske_keypad *keypad = platform_get_drvdata(pdev);
410 	int irq = platform_get_irq(pdev, 0);
411 
412 	if (device_may_wakeup(dev))
413 		disable_irq_wake(irq);
414 	else
415 		ske_keypad_set_bits(keypad, SKE_IMSC, 0x0, SKE_KPIMA);
416 
417 	return 0;
418 }
419 #endif
420 
421 static SIMPLE_DEV_PM_OPS(ske_keypad_dev_pm_ops,
422 			 ske_keypad_suspend, ske_keypad_resume);
423 
424 static struct platform_driver ske_keypad_driver = {
425 	.driver = {
426 		.name = "nmk-ske-keypad",
427 		.pm = &ske_keypad_dev_pm_ops,
428 	},
429 	.remove = ske_keypad_remove,
430 };
431 
432 module_platform_driver_probe(ske_keypad_driver, ske_keypad_probe);
433 
434 MODULE_LICENSE("GPL v2");
435 MODULE_AUTHOR("Naveen Kumar <naveen.gaddipati@stericsson.com> / Sundar Iyer <sundar.iyer@stericsson.com>");
436 MODULE_DESCRIPTION("Nomadik Scroll-Key-Encoder Keypad Driver");
437 MODULE_ALIAS("platform:nomadik-ske-keypad");
438